JP6067705B2 - System and method for temperature monitoring and control of multiple heater arrays - Google Patents

Description

  This application is entitled “A SYSTEM AND METHOD FOR MONITORING TEMPERATURE OF AND CONTROLLING MULTIPLETED HEATER ARRAY” under US Pat. No. 119 (e). Claims priority to US Provisional Application No. 61 / 524,546, filed August 17, 2011. This application is hereby incorporated by reference in its entirety.

  As semiconductor technology generations progress, substrate diameters tend to increase and transistor sizes tend to shrink, resulting in higher accuracy and reproducibility in substrate processing. Semiconductor substrate materials such as silicon substrates are processed by techniques including the use of vacuum chambers. These techniques include plasma applications such as sputtering deposition, plasma enhanced chemical vapor deposition (PECVD), resist stripping, and plasma etching as well as non-plasma applications such as electron beam deposition.

  The plasma processing systems available today are one of the semiconductor manufacturing tools that is experiencing a growing need for improved accuracy and reproducibility. One criterion for plasma processing systems is improved uniformity, which includes processing results for a series of substrates processed with nominally the same input parameters as well as uniformity of the processing results for the semiconductor substrate surface. The uniformity is also included. There is a desire for continuous improvement of uniformity on the substrate. Among other things, there is a need for a plasma chamber with improved uniformity, consistency, and self-diagnosis.

  Described herein is a system operable to perform temperature measurement and control of a multi-zone heating plate in a semiconductor support assembly used to support a semiconductor substrate in a semiconductor processing apparatus. The plate includes a plurality of planar heater zones, a plurality of diodes, a plurality of power supply lines, and a plurality of power return lines, each planar heater zone including one of the power supply lines and a power return line. There are not two planar heater zones that are connected to one of them and share the same pair of power supply line and power return line, and between each planar heater zone and the power supply line connected to it, Or between each flat heater zone and the power return line connected to it, the power return line to the power supply line through the flat heater zone The diodes are connected in series so that no current flows in the system, and the system is connected to the current measuring device and each line of the current return line to an electrical ground independent of the other power return lines. Or a first switch configuration configured to be selectively connected to the electrical isolation terminal, and each line of the current supply line to an electrical ground, independent of the other power supply lines, And a second switch configuration configured to selectively connect to the current measuring device or to the electrical isolation terminal.

1 is a schematic diagram of a cross section of a substrate support assembly that incorporates a heating plate with an array of planar heater zones and also includes an electrostatic chuck (ESC). FIG.

FIG. 6 illustrates a connection between a power supply line and a power return line and an array of planar heater zones in one embodiment of a heating plate that can be incorporated into a substrate support assembly.

1 is a schematic view of an exemplary plasma processing chamber that can include a substrate support assembly described herein. FIG.

It is the figure which showed the typical current-voltage characteristic (IV curve) of the diode connected to the planar heater zone in the heating plate.

FIG. 2 is a circuit diagram of a system according to one embodiment configured to control a heating plate and monitor the temperature of each planar heater zone therein.

FIG. 6 is a circuit diagram showing a circuit of a current measuring device in the system of FIG. 5.

  There is an increasing need to control substrate temperature in the radial and azimuthal directions in semiconductor processing equipment to achieve the desired micro-dimension (CD) uniformity on the substrate. Even slight variations in temperature may unacceptably affect the CD, which becomes more pronounced as the CD approaches 100 nm or less in the semiconductor manufacturing process.

  The substrate support assembly may be configured for a variety of functions during processing, such as supporting the substrate, adjusting the substrate temperature, and supplying radio frequency power. The substrate support assembly can include an electrostatic chuck (ESC) useful for electrostatically clamping the substrate to the substrate support assembly during processing. The ESC may be an adjustable ESC (T-ESC). T-ESCs are described in commonly assigned US Pat. Nos. 6,847,014 and 6,921,724, which are incorporated herein by reference. The substrate support assembly includes a ceramic substrate holder, a fluid cooling heat sink (hereinafter referred to as a cooling plate), and a plurality of concentric planar heater zones for achieving stepwise temperature control in the radial direction. Good. Usually, the cold plate is maintained between 0 ° C and 30 ° C. The heater is positioned on the cooling plate with a layer of thermal insulation interposed therebetween. The heater can maintain the support surface of the substrate support assembly at a temperature that is about 0-80 ° C. above the cold plate temperature. By changing the heater power in the plurality of planar heater zones, the substrate support temperature distribution can be changed between a hot center, a cold center, and a uniform state. Furthermore, the average substrate support temperature can be changed stepwise within an operating range of 0-80 ° C. above the cold plate temperature. As CD decreases with advances in semiconductor technology, slight variations in temperature in the azimuthal direction become an increasingly significant issue.

  Controlling temperature is not an easy task for several reasons. First, many factors such as the location of the heat source and heat sink, medium movement, material, and shape can affect heat transfer. Second, heat transfer is a dynamic process. As long as the system in question is not in thermal equilibrium, heat transfer occurs and the temperature distribution and heat transfer change over time. Third, non-equilibrium phenomena such as plasma that are always present during plasma processing are very difficult, if not impossible, to theoretically predict the heat transfer behavior of any practical plasma processing equipment. To.

  The substrate temperature distribution in the plasma processing apparatus is influenced by many factors such as the plasma density distribution, the RF power distribution, and the detailed structure of various heating elements and cooling elements in the chuck. In this case, it is not uniform and is difficult to control with a small number of heating or cooling elements. This defect leads to processing speed non-uniformity across the substrate and device die micro-dimensional non-uniformity on the substrate.

  In light of the complexity of temperature control, a plurality of independently controllable planar heater zones are incorporated into the substrate support assembly to allow the apparatus to actively create and maintain the desired spatial and temporal temperature distribution, and CD It would be advantageous to be able to counteract other harmful factors that affect the uniformity of the

  A heating plate for a substrate support assembly with a plurality of independently controllable planar heater zones in a semiconductor processing apparatus is disclosed in commonly owned U.S. Patent Publication No. 2011/0092072, the disclosure of which is incorporated herein by reference. It is disclosed. The heating plate includes a scalable multi-layout planar heater zone, a power supply line, and a power return line. By adjusting the power of the planar heater zone, the temperature distribution during processing can be shaped in both radial and azimuthal directions. This heating plate is mainly described for a plasma processing apparatus, but can also be used for other semiconductor processing apparatuses that do not use plasma.

The planar heater zones in the heating plate are preferably arranged in a predetermined pattern such as, for example, a rectangular grid, a hexagonal grid, a polar array, concentric circles, or any desired pattern. Each planar heater zone may be of any suitable size and may have one or more heater elements. In certain embodiments, all heater elements in the planar heater zone are turned on or off at the same time. In order to minimize the number of electrical connections, the power supply lines and power return lines are connected so that each power supply line is connected to a different group of planar heater zones and each power return line is in a different group. Arranged to be connected to a planar heater zone, where each planar heater zone enters one of the groups connected to a specific power supply line and one of the groups connected to a specific power return line ing. In certain embodiments, there are not two planar heater zones connected to the same power supply line and power return line pair. Thus, the planar heater zone can be activated by causing a current to flow through the pair of power supply line and power return line to which the planar heater zone is connected. The power of the heater element is preferably less than 20 W, more preferably 5 to 10 W. The heater element is a resistance heater such as a polyimide heater, a silicone rubber heater, a mica heater, a metal heater (for example, W, Ni / Cr alloy, Mo, or Ta), a ceramic heater (for example, WC), a semiconductor heater, or a carbon heater. It may be. The heater element may be a screen printed heater, a wire wound heater, or a foil etched heater. In one embodiment, each planar heater zone is no more than four device dies manufactured on a semiconductor substrate, or no more than two device dies manufactured on a semiconductor substrate, or manufactured on a semiconductor substrate. is device die one minute or less which are, or 16～100Cm ² in the area so as to correspond to the device die on the substrate, 1～15Cm ^2, or 2-3 cm ^2. The thickness of the heater element can be from 2 micrometers to 1 millimeter, preferably 5 to 80 micrometers. To ensure space between the planar heater zones and / or between the planar heater zones and the power supply and power return lines, the total area of the planar heater zones is 90% of the area of the top surface of the substrate support assembly. %, For example, 50 to 90% of the area. The power supply line or power return line (collectively referred to as the power line) may be placed in a 1-10 mm gap between the planar heater zones or separated from the plane heater zone surface by an electrical insulation layer. It may be arranged in the plane. In order to carry high currents and reduce joule heating, the power supply lines and power return lines are preferably made as wide as space permits. In one embodiment where the power line is in the same plane as the planar heater zone, the width of the power line is preferably between 0.3 mm and 2 mm. In another embodiment where the power line is on a different surface than the planar heater zone, the width of the power line may be as large as the planar heater zone, eg 1-2 inches (about 2 inches for a 300 mm chuck). .54-5.08 cm). The material of the power line may be the same as or different from the material of the heater element. Preferably, the material of the power line is a low resistance material such as copper Cu, aluminum Al, tungsten W, Inconel (registered trademark), or molybdenum Mo.

  1-2 illustrate a substrate support assembly that includes one embodiment of a heating plate having an array of planar heater zones 101 incorporated into two electrically insulating layers 104A and 104B. The electrically insulating layer may be a polymer material, or an inorganic material, or a ceramic such as silicon oxide, alumina, yttria, aluminum nitride, or other suitable material. The substrate support assembly further includes (a) an ESC having a ceramic layer 103 (electrostatic clamping layer) embedded with electrodes 102 (eg, monopolar or bipolar) to electrostatically clamp the substrate to the surface by a DC voltage; (B) a thermal barrier layer 107 and (c) a cooling plate 105 including a flow path 106 for flowing a coolant.

  As shown in FIG. 2, each planar heater zone 101 is connected to one of the power supply lines 201 and one of the power return lines 202. There are not two planar heater zones 101 sharing the same pair of power supply line 201 and power return line 202. With a suitable electrical switch configuration, the paired power supply line 201 and power return line 202 are connected to a power supply (not shown) so that only the planar heater zone connected to this pair of power lines is on. To be. The time average heating power of each planar heater zone can be individually adjusted by time domain multiplexing. To prevent mutual interference between different planar heater zones (as shown in FIG. 2) between each heater zone and its connected power supply line 201, or each heater zone and its connected power return A diode 250 is connected in series between the line 202 (not shown) so that no current flows from the power return line 201 to the power supply line 202 via the planar heater zone 101. The diode 250 is physically positioned within or adjacent to the planar heater zone.

  The substrate support assembly can include one embodiment of a heating plate, each planar heater zone of the heating plate having a substrate temperature and consequently a plasma etching process controlled for each device die position of the device from the substrate. The size is comparable or smaller than a device die or group of device dies on the substrate so that yield can be maximized. The heating plate can include 10-100, 100-200, 200-300, or more planar heater zones. The scalable structure of the hot plate has a minimum number of power supply lines, power return lines, and feedthroughs in the cold plate that allow the number of planar heater zones required for substrate temperature control per die (on a 300 mm substrate, (There are usually over 100 dies, and therefore there are over 100 heater zones), thereby reducing obstacles that disturb the substrate temperature, manufacturing costs, and complexity of the substrate support assembly. it can. Although not shown in the figure, the substrate support assembly includes lift pins for lifting the substrate, helium backside cooling, a temperature sensor for providing a temperature feedback signal, a voltage and current sensor for providing a heating power feedback signal, Features such as a power supply for the heater and / or clamp electrode, and / or an RF filter may be included.

  As an overview of how the plasma processing chamber operates, FIG. 3 shows a schematic of the plasma processing chamber having an upper showerhead electrode 703 and a substrate support assembly 704 disposed therein. The substrate 712 is taken in through the take-in port 711 and placed on the substrate support assembly 704. The gas line 709 supplies a process gas to the upper showerhead electrode 703, and the showerhead electrode 703 feeds the process gas into the chamber. Connected to the gas line 709 is a gas source 708 (eg, mass flow controller power that provides appropriate gas mixing). An RF power source 702 is connected to the upper showerhead electrode 703. In operation, the chamber is evacuated by the vacuum pump 710 to activate the process gas into a plasma in the space between the substrate 712 and the upper showerhead electrode 703 and above the substrate support assembly 704. RF power is capacitively coupled between the showerhead electrode 703 and the lower electrode. The plasma can be used to etch device die features into layers on the substrate 712. The substrate support assembly 704 may incorporate a heater therein. It should be understood that although the detailed design of the plasma processing chamber is variable, RF power is coupled to the plasma through the substrate support assembly 704.

  The power supplied to each planar heater zone 101 can be adjusted based on the actual temperature of that zone to achieve the desired substrate support temperature distribution. The actual temperature in each planar heater zone 101 can be monitored by measuring the reverse saturation current of the diode 250 connected to that zone. FIG. 4 shows a typical current-voltage characteristic (IV curve) of the diode 250. When the diode 250 is in its reverse bias region (the region marked by the shaded frame 401), the current through the diode 250 is essentially independent of the bias voltage across the diode 250. The magnitude of this current is called reverse saturation current Ir. The temperature dependence of Ir can be approximated as follows.

  Here, A is the area of the junction of the diode 250, T is the temperature of the diode 250 expressed in Kelvin, γ is a constant, and Eg is the material constituting the junction. Energy gap (Eg = 1.12 eV for silicon) and k is the Boltzmann constant.

  FIG. 5 is configured to control the heating plate by measuring the reverse saturation current Ir of the diode 250 connected to each planar heater zone 101 and to monitor the temperature of each planar heater zone 101 therein. A circuit diagram of the system 500 is shown. For clarity, only four planar heater zones are shown. The system 500 can be configured to operate with any number of planar heater zones.

  System 500 includes a current measurement device 560, a switch configuration 1000, a switch configuration 2000, an optional on-off switch 575, and an optional calibration device 570. Switch configuration 1000 is configured to selectively connect each power return line 202 to electrical ground, to voltage source 520, or to an electrically isolated terminal independently of the other power return lines. Switch configuration 2000 is configured to selectively connect each current supply line 201 to electrical ground, to power source 510, to current measuring device 560, or to an electrical isolation terminal, independent of the other power supply lines. Composed. The voltage source 520 supplies a non-negative voltage. An optional calibration device 570 can be provided to calibrate the relationship between the reverse saturation current Ir of each diode 250 and its temperature T. The calibration instrument 570 includes a calibration heater 571 that is thermally isolated from the planar heater zone 101 and the diode 250, a calibrated thermometer 572 (eg, a thermocouple), and the same type (preferably the same) calibration as the diode 250. A diode 573. Calibration instrument 570 can be located within system 500. The calibration heater 571 and the thermometer 572 can be energized by a voltage source 520. The cathode of calibration diode 573 is configured to connect to voltage source 520 and the anode is connected to current measurement instrument 560 through on-off switch 575 (ie, calibration diode 573 is reverse biased). The calibration heater 571 maintains the calibration diode 573 at a temperature close to the operating temperature of the planar heater zone 101 (for example, 20 to 200 ° C.). A processor 5000 (eg, a microcontroller unit, computer, etc.) controls the switch configurations 1000 and 2000, the calibration device 570, and the switch 575, receives current readings from the current measurement device 560, and reads temperature readings from the calibration device 570. Receive value. If desired, the processor 5000 can be included in the system 500.

  The current measurement device 560 may be any suitable device, such as an amp meter or an operational amplifier (op amp) based device, as shown in FIG. The measured current flows to the input terminal 605, which is connected to the inverting input 601a of the operational amplifier 601 through an optional capacitor 602. The inverting input 601a of the operational amplifier 601 is also connected to the output 601c of the operational amplifier 601 through the resistor 603 of the resistor RI. The non-inverting input 601b of the operational amplifier 601 is connected to electrical ground. The voltage V applied to the output terminal 606 connected to the output of the operational amplifier 601 is a read value of the current I, and V = I × RI. The instrument shown in FIG. 6 is a voltage signal on the output terminal 606 that is sent to the processor 5000 as a temperature reading from the current signal of the diode (one of the diodes 250 or the calibration diode 573) on the input terminal 605. Convert to

  The method for temperature measurement and control of the heating plate includes a temperature measurement step, which includes connecting a power supply line 201 connected to the planar heater zone 101 to the current measurement instrument 560 and all other steps. Connecting the power supply line (one or more) to electrical ground, connecting the power return line connected to the planar heater zone 101 to the voltage source 520, and all other (one or more) Connecting the power return line to the electrical isolation terminal, obtaining a current reading of the reverse saturation current of the diode 250 connected in series with the planar heater zone 101 from the current measuring instrument 560, and reading the current based on Equation 1 The temperature T of the flat heater zone 101 is calculated from the value, and the desired temperature distribution for the entire heating plate is calculated for the flat heater zone 101. Estimating the fixed point temperature T0, and calculating a duration t such that energizing the planar heater zone 101 for the duration t by the power supply unit 510 changes the temperature of the planar heater zone 101 from T to T0. including. By connecting all the power supply lines not connected to the planar heater zone 101 to electrical ground, only the reverse saturation current from the diode 250 connected to the planar heater zone 101 can reach the current measuring device 560. Guaranteed.

  The method further includes an energization step after the temperature measurement step, and the energization step includes a connection between the power supply line 201 connected to the planar heater zone 101 and the power supply unit 510, and the planar heater zone 101. Maintaining the connection between the power return line 202 connected to and electrical ground for a duration t. The method further includes repeating the temperature measurement step and the energization step for each planar heater zone 101.

  The method can further include an optional discharge step prior to performing the temperature measurement step on the planar heater zone 101, which discharges the junction capacitance of the diode 250 connected to the planar heater zone 101. To ground the power supply line 201 connected to the planar heater zone 101.

  The method may further include an optional zero point correction step prior to performing a temperature measurement step on the planar heater zone 101, which includes a power supply line 201 connected to the planar heater zone 101. Connect to the current measuring device 560, connect all other (one or more) power supply lines to electrical ground, and connect the power return line connected to the planar heater zone 101 to electrical ground. Connecting each line of the other power return lines to an electrically insulated terminal and obtaining a current reading (zero current) from the current measuring device 560. The zero point current can be subtracted from the current reading in the temperature measurement step before calculating the temperature T of the planar heater zone. The zero point correction step eliminates an error derived from a leakage current generated from the power supply unit 510 via the switch configuration 2000. The measurement step, zeroing step, and discharging step may all be performed at a rate sufficient to use synchronous detection on the output of operational amplifier 601 by controller 5000 or additional synchronous detection electronics. Synchronous detection of measurement signals will reduce measurement noise and improve accuracy.

  The method can further include an optional calibration step to correct the temperature dependent time shift of the reverse saturation current of any diode 250. The calibration step includes disconnecting all power supply lines 201 and power return lines 202 from the current measuring instrument 560, closing the on-off switch 575, and calibrating the diode 573 by the calibration heater 571, preferably the operating temperature of the diode 250. Heating to a temperature within the range, measuring the temperature of the calibration diode 573 with a calibrated thermometer 572, measuring the reverse saturation current of the calibration diode 573, the measured temperature and the measured inverse Adjusting the parameters A and γ in Equation 1 for each diode 250 based on the saturation current.

  A method of processing a semiconductor in a plasma etching apparatus that includes a substrate support assembly and a system described herein includes: (a) supporting the semiconductor substrate on the substrate support assembly; and (b) in a heating plate. By energizing the planar heater zone by the system, a desired temperature distribution is formed over the entire heating plate, (c) the process gas is activated to form plasma, and (d) the semiconductor is etched by the plasma. And (e) maintaining the desired temperature distribution using the system while etching the semiconductor with the plasma. In step (e), the system maintains the desired temperature distribution by measuring the temperature of each flat heater zone in the heating plate and energizing each flat heater zone based on the measured temperature. The system measures the temperature of each planar heater zone by taking a current reading of the reverse saturation current of a diode connected in series with that planar heater zone.

からパラメータＡ及びγの少なくとも１つを決定する、
方法。
［適用例１８］適用例１０に記載のプラズマエッチング装置において半導体基板を処理する方法であって、下記各ステップ
（ａ）前記基板サポートアセンブリ上で半導体基板を支え、
（ｂ）前記加熱板のなかの前記平面ヒータゾーンを前記システムによって通電することによって、前記加熱板全域にわたって所望の温度分布を形成し、
（ｃ）プロセスガスを活性化させてプラズマにし、
（ｄ）前記プラズマによって前記半導体基板をエッチングし、
（ｅ）前記プラズマによって前記半導体基板をエッチングする間、前記システムを使用して前記所望の温度分布を維持する、
を備える方法。
［適用例１９］適用例１８に記載の方法であって、
ステップ（ｅ）において、前記システムは、前記加熱板のなかの各平面ヒータゾーンの温度を測定し、その測定された温度に基づいて各平面ヒータゾーンを通電することによって、前記所望の温度分布を維持する、方法。
［適用例２０］適用例１９に記載の方法であって、
前記システムは、前記平面ヒータゾーンに直列に接続された前記ダイオードの逆飽和電流の電流読み取り値を得ることによって、各平面ヒータゾーンの温度を測定する、方法。 Although the system 500 and the method for performing temperature measurement and control of the heating plate have been described in detail with reference to specific embodiments thereof, those skilled in the art will depart from the scope of the appended claims. Obviously, various changes and modifications may be made without departing from the equivalent, and equivalents may be employed. For example, the present invention can be implemented as the following application examples.
Application Example 1 A system operable to perform temperature measurement and control of a multi-zone heating plate in a semiconductor support assembly used to support a semiconductor substrate in a semiconductor processing apparatus, the heating plate comprising: A plurality of planar heater zones, a plurality of diodes, a plurality of power supply lines, and a plurality of power return lines, each planar heater zone comprising one of the power supply lines and one of the power return lines One flat heater zone connected to one does not share a pair of a power supply line and a power return line with another flat heater zone, and each flat heater zone and a power supply line connected thereto Or between each planar heater zone and the power return line connected to it, from the power return line through the planar heater zone, the power Diode so as not to flow a current in a direction leading to feed lines are connected in series, the system comprising:
A current measuring device;
A first switch configuration configured to selectively connect each line of the current return line to an electrical ground, to a voltage supply, or to an electrical isolation terminal independently of the other power return lines; ,
Each line of the current supply line is configured to be selectively connected to the electrical ground, to a power supply unit, to the current measuring device, or to an electrical insulation terminal independently of other power supply lines. A second switch configuration;
A system comprising:
Application Example 2 The system according to Application Example 1, further including:
An on / off switch;
A calibration device connected to the current measuring device through the on / off switch and configured to connect to the voltage supply;
A system comprising:
[Application Example 3] The system according to Application Example 1,
The voltage supply unit outputs a non-negative voltage.
[Application Example 4] The system according to Application Example 1,
The current measurement device is an amplifier meter and / or includes an operational amplifier.
[Application Example 5] The system according to Application Example 2,
The calibration instrument includes a calibration heater, a calibrated thermometer, and a calibration diode configured to connect its anode to the current measurement instrument through the on-off switch and to connect its cathode to the voltage supply. ,system.
[Application Example 6] The system according to Application Example 5,
The calibration diode of the calibration instrument is the same as the diode connected to the planar heater zone in the heating plate.
[Application Example 7] The system according to Application Example 1,
Each size of the planar heater zone is 16-100 cm ² . system.
[Application Example 8] The system according to Application Example 1,
The system wherein the heating plate includes 10-100, 100-200, 200-300, or more planar heater zones.
Application Example 9 A plasma processing apparatus including a substrate support assembly and the system described in Application Example 1, wherein the system is used for supporting a semiconductor substrate in the semiconductor processing apparatus. A plasma processing apparatus operable to perform temperature measurement and control of each heater zone of the multi-zone heating plate.
Application Example 10 The plasma processing apparatus according to Application Example 9,
A plasma processing apparatus which is a plasma etching apparatus.
Application Example 11 A method of measuring the temperature of the system of Application Example 1 and maintaining a desired temperature distribution throughout the system,
A temperature measurement step,
The temperature measuring step includes
Connecting a power supply line connected to one of the planar heater zones to the current measuring instrument;
Connect all other (one or more) power supply lines to electrical ground,
Connecting a power return line connected to the planar heater zone to the voltage supply;
Connect all other (one or more) power return lines to the electrical isolation terminals,
Obtaining a current reading of the reverse saturation current of the diode connected in series to the planar heater zone from the current measuring instrument;
Calculate the temperature T of the flat heater zone from the current reading,
Estimating the set point temperature T0 for the planar heater zone from the desired temperature distribution for the entire heating plate,
The duration t is calculated such that energizing the planar heater zone for the duration t by the power supply unit changes the temperature of the planar heater zone from T to T0.
A method involving that.
[Application Example 12] The method according to Application Example 11, further comprising:
An energization step after the temperature measurement step;
The energizing step includes
A connection between the power supply line connected to the planar heater zone and the power supply, and a connection between the power return line connected to the planar heater zone and the electrical ground, Maintaining for said duration t.
[Application Example 13] The method according to Application Example 12, further comprising:
A method of repeating the temperature measurement step and / or the energization step for each of the planar heater zones.
[Application Example 14] The method according to Application Example 11, further comprising:
Comprising an optional discharge step prior to performing the temperature measurement step on the planar heater zone;
The discharging step includes
Grounding the power supply line connected to the planar heater zone to discharge the junction capacitance of the diode connected to the planar heater zone.
[Application Example 15] The method according to Application Example 11, further comprising:
Before performing the temperature measurement step on the flat heater zone, comprising a zero point correction step,
The zero point correcting step includes:
Connecting the power supply line connected to the planar heater zone to the current measuring device;
Connect all other (one or more) power supply lines to the electrical ground;
Connecting the power return line connected to the planar heater zone to the electrical ground;
Connect each of the other power return lines to an electrically insulated terminal,
Get current reading (zero current) from the current measuring device
Method.
[Application Example 16] The method according to Application Example 15,
The current measuring step further comprises:
Subtracting the zero current from a current reading of the reverse saturation current before calculating the temperature T of the planar heater zone.
Application Example 17 A method for calibrating the diode in the system according to Application Example 6, comprising:
Disconnect all power supply lines and power return lines from the current measuring instrument,
Close the on-off switch;
The calibration heater heats the calibration diode to a temperature within the operating temperature range of the diode;
Measuring the temperature of the calibration diode with the calibrated thermometer;
Measuring the reverse saturation current of the calibration diode;
A is the area of the junction of the diode, T is the temperature of the diode expressed in Kelvin, γ is a constant, Eg is the energy gap of the material constituting the junction (Eg = 1.12 eV for silicon) ), Where k is the Boltzmann constant, based on the measured temperature and the measured reverse saturation current, for each diode

Determining at least one of parameters A and γ from
Method.
[Application Example 18] A method for processing a semiconductor substrate in the plasma etching apparatus according to Application Example 10, wherein the following steps are performed:
(A) supporting a semiconductor substrate on the substrate support assembly;
(B) energizing the planar heater zone in the heating plate by the system to form a desired temperature distribution across the heating plate;
(C) Activate the process gas into plasma,
(D) etching the semiconductor substrate with the plasma;
(E) maintaining the desired temperature distribution using the system while etching the semiconductor substrate with the plasma;
A method comprising:
[Application Example 19] The method according to Application Example 18,
In step (e), the system measures the temperature of each planar heater zone in the heating plate and energizes each planar heater zone based on the measured temperature, thereby obtaining the desired temperature distribution. How to maintain.
[Application Example 20] The method according to Application Example 19,
The system measures the temperature of each planar heater zone by obtaining a current reading of the reverse saturation current of the diode connected in series to the planar heater zone.

Claims (20)

A system operable to perform temperature measurement and control of a multi-zone heating plate in a semiconductor support assembly used to support a semiconductor substrate in a semiconductor processing apparatus, the heating plate comprising a plurality of planar heater zones And a plurality of diodes, a plurality of power supply lines, and a plurality of power return lines, each planar heater zone connected to one of the power supply lines and one of the power return lines One flat heater zone does not share a pair of power supply line and power return line with another flat heater zone, and between each flat heater zone and the power supply line connected thereto, or each Between the flat heater zone and the power return line connected thereto, the power return line passes through the flat heater zone to the power supply line. That direction a diode as not to flow the electric current are connected in series, the system comprising:
A current measuring device;
A first switch configuration configured to selectively connect each line of the power return line to an electrical ground, to a voltage supply, or to an electrical isolation terminal independently of the other power return lines; ,
Each line of the power supply line is configured to be selectively connected to the electrical ground, to a power supply unit, to the current measuring device, or to an electrical insulation terminal independently of other power supply lines. A second switch configuration;
A system comprising: The system of claim 1, further comprising:
An on- off switch;
A calibration device connected to the current measuring device through the on- off switch and configured to connect to the voltage supply;
A system comprising: The system of claim 1, comprising:
The voltage supply unit outputs a non-negative voltage. The system of claim 1, comprising:
The current measuring device is an amplifier meter and / or includes an operational amplifier. The system of claim 2, comprising:
The calibration device includes a calibration heater configured to connect a calibration heater, a calibrated thermometer, and an anode thereof to the current measuring device through the on-off switch and a cathode thereof to the voltage supply unit. Including the system. 6. The system according to claim 5, wherein
The calibration diode of the calibration instrument is the same as the diode connected to the planar heater zone in the heating plate. The system of claim 1, comprising:
Each size of the planar heater zone is 16-100 cm ² . system. The system of claim 1, comprising:
The system wherein the heating plate includes 10-100, 100-200, 200-300, or more planar heater zones.   A plasma processing apparatus comprising a substrate support assembly and the system of claim 1, wherein the system is the multi-zone in the semiconductor support assembly used to support a semiconductor substrate in the semiconductor processing apparatus. A plasma processing apparatus operable to perform temperature measurement and control of each heater zone of the heating plate. The plasma processing apparatus according to claim 9, wherein
A plasma processing apparatus which is a plasma etching apparatus. A method of measuring the temperature of the system of claim 1 and maintaining a desired temperature distribution throughout the system comprising:
A temperature measurement step,
The temperature measuring step includes
Connecting a power supply line connected to one of the planar heater zones to the current measuring device ;
Connect all other (one or more) power supply lines to electrical ground,
Connecting a power return line connected to the planar heater zone to the voltage supply;
Connect all other (one or more) power return lines to the electrical isolation terminals,
Performing a current measurement step of obtaining a current reading of reverse saturation current of the diode connected in series to the planar heater zone from the current measurement device ;
Calculate the temperature T of the flat heater zone from the current reading,
Estimating the set point temperature T0 for the planar heater zone from the desired temperature distribution for the entire heating plate,
Calculating a duration t such that energizing the planar heater zone by the power supply for a duration t changes the temperature of the planar heater zone from T to T0. The method of claim 11, further comprising:
An energization step after the temperature measurement step;
The energizing step includes
A connection between the power supply line connected to the planar heater zone and the power supply, and a connection between the power return line connected to the planar heater zone and the electrical ground, Maintaining for said duration t. The method of claim 12, further comprising:
A method of repeating the temperature measurement step and / or the energization step for each of the planar heater zones. The method of claim 11, further comprising:
Comprising an optional discharge step prior to performing the temperature measurement step on the planar heater zone;
The discharging step includes
Grounding the power supply line connected to the planar heater zone to discharge the junction capacitance of the diode connected to the planar heater zone. The method of claim 11, further comprising:
Before performing the temperature measurement step on the flat heater zone, comprising a zero point correction step,
The zero point correcting step includes:
Connecting the power supply line connected to the planar heater zone to the current measuring device ;
Connect all other (one or more) power supply lines to the electrical ground;
Connecting the power return line connected to the planar heater zone to the electrical ground;
Connect each of the other power return lines to an electrically insulated terminal,
A method for obtaining a current reading (zero current) from the current measuring device . 16. A method according to claim 15, comprising
The current measuring step further comprises:
Subtracting the zero current from a current reading of the reverse saturation current before calculating the temperature T of the planar heater zone. A method of calibrating the diode in the system of claim 6 comprising:
Disconnect all power supply lines and power return lines from the current measuring device ,
Close the on-off switch;
The calibration heater heats the calibration diode to a temperature within the operating temperature range of the diode;
Measuring the temperature of the calibration diode with the calibrated thermometer;
Measuring the reverse saturation current of the calibration diode;
A is the area of the junction of the diode, T is the temperature of the diode expressed in Kelvin, γ is a constant, Eg is the energy gap of the material constituting the junction (Eg = 1.12 eV for silicon) ), Where k is a Boltzmann constant, for each diode based on the measured temperature and the measured reverse saturation current Ir

Determining at least one of parameters A and γ from
Method. A method for processing a semiconductor substrate in the plasma etching apparatus according to claim 10, comprising: (a) supporting the semiconductor substrate on the substrate support assembly;
(B) energizing the planar heater zone in the heating plate by the system to form a desired temperature distribution across the heating plate;
(C) Activate the process gas into plasma,
(D) etching the semiconductor substrate with the plasma;
(E) maintaining the desired temperature distribution using the system while etching the semiconductor substrate with the plasma;
A method comprising: The method according to claim 18, comprising:
In step (e), the system measures the temperature of each planar heater zone in the heating plate and energizes each planar heater zone based on the measured temperature, thereby obtaining the desired temperature distribution. How to maintain. 20. The method according to claim 19, comprising
The system measures the temperature of each planar heater zone by obtaining a current reading of the reverse saturation current of the diode connected in series to the planar heater zone.

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